This invention relates to medical devices, methods for making them, and methods for their use. More particularly, the present invention relates to the methods and devices for occluding body lumens by delivering a plugging means into a lumen with or through a detachable access catheter. In one exemplary use, The invention may be used to occlude the cystic duct for preventing bile leakage in the field of treating gallstone and gallbladder disease.
Bile is first produced in the liver, then secreted into a complex network of ducts, and eventually enters into the hepatic duct. The bile then passes through the cystic duct and enters into the gallbladder. The cystic duct is at the narrow end of the gallbladder. It is the passage by which the contents of the gallbladder drain into another slightly larger tube called the common bile duct. The gallbladder concentrates and stores bile. When food enters the small intestine, a hormone called cholecystokinin is released, signaling the gallbladder to contract. The contraction of the gallbladder propels the bile back through the cystic duct and into the common bile duct, which leads bile into the duodenum. The bile then emulsifies fatty molecules so that fat and the fat-soluble vitamins A, D, E, and K can be absorbed through the intestinal lining. A sphincter is present at the duct-duodenum juncture.
Bile is composed of water, bile salts, lecithin and cholesterol. Cholesterol makes up only {fraction (1/20)} of bile. It is not very soluble and must be properly balanced with bile salts to remain suspended in fluid. If the liver secretes too much cholesterol into the bile, cholesterol may then precipitate out of the bile solution to form gallstones, a condition known as cholelithiasis.
Gallstones are quite prevalent in most western countries. Cholelithiasis incidence increases with age. In the United States, at least ⅕ of women, and {fraction (2/25)} of men over the age of 40 are affected by gallstones. More than 20 million people in the U.S. have gallstones, and approximately 1 million new cases of cholelithiasis develop every year.
Gallstones usually produce noticeable symptoms by causing inflammation, narrowing (stenosis) or obstruction of the cystic duct, common bile duct or sphincter following their exit from the gallbladder. Although there has been some success with drug- or shockwave-mediated dissolution of gallstones, the current therapy of choice is surgery, either by excision of the gallbladder (cholecystectomy) or draining the gallbladder with a tube (cholecystostomy). Harrison""s Principles of Internal Medicine, Twelfth Edition, McGraw-Hill, Inc., New York, N.Y., pp. 1358-1368 (1991). In 1991 approximately 600,000 patients underwent cholecystectomy. Gallstones and Laparoscopic Cholecystectomy, NIH Consens Statement Online Sep. 14-16, 1992, 10(3):1-20. Jun. 25, 2001  less than http://odp.od.nih.gov/consensus/cons/090/090_statement.htm greater than .
Traditionally, there are two ways to perform a cholecystectomy: an open cholecystectomy and a laparoscopic cholecystectomy. In an open cholecystectomy, the surgeon removes the gallbladder through a 2 to 4 inch incision in the patient""s abdomen. In a laparoscopic cholecystectomy, the surgeon inserts a laparoscope into the patient""s body through a tiny cut (xc2xcxe2x80x3-b {fraction (1/2)}xe2x80x3) made just below the patient""s navel. A laparoscope is a long, slender optical instrument that has lenses and a powerful light. The laparoscope is attached to a television camera and allows the surgeon to see the patient""s gallbladder on a television screen and do the surgery with tools inserted in three other small cuts made in the right upper part of the patient""s abdomen. The surgeon removes the gallbladder through one of the incisions. The advantages of laparoscopic cholecystectomy over open cholecystectomy are shorter postoperative recovery time, less pain and better cosmetic results.
The technical problems of dissecting the gallbladder from the liver include stone spillage with puncture site infection, liver bed bleeding, and difficult removal of the stone laden gallbladder through a 1-cm incision. These potential problems can be eliminated by a new method which combines lithotriptic emulsification (mechanical liquification) of gallstones with removal of the free gallbladder wall and ablation of the remaining gallbladder mucosa. Schultz, L. S., Cartmill, J. A., Graber, J. N., Hickok, D. F. xe2x80x9cLaparolithic cholecystectomy: Laboratory data and first clinical case.xe2x80x9d J. Clinical Laser Medicine and Surgery 11.3 (1993): 135-137.
Whichever the technique is used, the surgeon must dissect the cystic artery and duct and occlude them with metal clips or ligature before removal of the gallbladder. The cystic duct clip or ligature prevents spillage of bile from the gallbladder and its leakage from the liver. Bile leakage from the cystic duct is one of the most common problems following the cholecystectomy. The leakage could be due to incomplete duct occlusion or dislodgement of a loosely placed clip or ligature from the cystic duct stump. Further, the clip may migrate into the common bile duct, where it can induce cholesterol stones, resulting in severe abdominal and back pain. Experts in the field recommend that surgeons exercise great care to ensure secure occlusion of the cystic duct during the cholecystectomy. At the present time, occlusion of the cystic duct is to be considered permanent although future research may indicate benefits from temporary occlusion.
Occlusion of the cystic duct can also be a helpful adjunct in combination with percutaneous transhepatic catheter lithotripsy and cholecystostomy for treatment of acute acalculous cholecystitis as may be seen following cardiac bypass surgery. Acute acalculous cholecystitis is inflammation of the gallbladder without calculi. In the study period 1982-1990, 0.34% of the patients following open heart surgery developed acute acalculous cholecystitis. Some causes of acute acalculous cholecystitis include hypoperfusion of the gallbladder due to cardiovascular bypass surgery, visceral atherosclerosis, or low cardiac output.
Although the management of acute acalculous cholecystitis following heart surgery remains controversial, percutaneous transhepatic gallbladder drainage is found to be a safe and effective procedure. Ishikawa, S., Ohtaki, A., Koyano T., Takahashi T., Sato, Y., Nakamura, S., Ohwada, S., Morishita, Y.; xe2x80x9cPercutaneous transhepatic gallbladder drainage for acute acalculous cholecystitis following cardiovascular surgery.xe2x80x9d J. Cardiovasc. Surg. 38.5 (1997): 513-5. The drainage (cholecystostomy) is for temporary management (to get over infection), and at the present time, cystic duct occlusion is permanent and should be part of gallbladder removal or, in this case, defunctionalization. In such cases, catheter-guided occlusion of the cystic duct would be an useful, adjunctive therapy in conjunction with chemical or mechanical ablation of the mucosa to defunctionalize the gallbladder.
There is a need in the art for an alternative method and device of occlusion of body lumens. There is a further need for a method and device of secure occlusion of the cystic duct to prevent bile spillage during and after non-surgical methods of defunctionalization of the gallbladder as an alternative to open or laparoscopic surgery.
This invention provides devices and methods for occluding a body lumen. According to one embodiment of the invention, the lumen occluding device comprises means for plugging the body lumen and means for fixing the means for plugging in place.
In one embodiment, the means for plugging comprises a tapered segment, and the means for fixing comprises an expandable segment which is generally adjacent to the tapered segment. In another embodiment, the expandable segment further includes structures suitable for attaching the expandable segment to the interior wall of the lumen. In some embodiments, the structures for attaching the means for plugging to the interior wall of the lumen have a shape like tooth, or hook, or the like. In other embodiments, the means for fixing comprises a segment having numerous openings of suitable sizes, shapes, and spaces between them.
In some embodiments, the occlusion device of the present invention comprises a delivery instrument detachably coupled to the means for plugging. In one embodiment, the delivery instrument comprises an access catheter separably coupled to the means for plugging, and a maneuverable catheter core flexibly placed inside the catheter.
In one embodiment of the method of the present invention, using a suitable delivery instrument, the means for plugging is inserted into a target lumen, moved to a selected location, and then fixed to the interior wall of the lumen. The delivery instrument is then detached from the means for plugging and withdrawn from the lumen, leaving the means for plugging in the selected location as an occluding device. While at the present time, and as concerns occlusion of the cystic duct, the present assertion may be used to permanently plug or occlude a body lumen, the present invention is intended to encompass semi-permanent or temporary plugging or occlusion of body lumens.
In some embodiments of the method, the lumen occluding device is inserted into the body lumen, such as the cystic duct, through an incision in an abdominal wall of a human patient. In another embodiment of the method, the occluding device may be inserted into the fallopian tubes for plugging or occlusion providing for contraception.
In another embodiment of the method of the present invention, the means for plugging is advanced to the selected location of a body lumen, then a portion of it is expanded against the interior wall of the lumen and thereby occludes the lumen. The delivery instrument is then detached and removed from the body lumen.
In another embodiment of the method, a means for plugging with numerous openings is inserted into a selected location of a body lumen, then a biological bonding agent is injected into its delivery instrument. After delivery to the occluding device, the biological bonding agent is extruded through the openings and binds the means for plugging to the interior wall of the lumen. The delivery instrument is then detached and withdrawn from the lumen.
The illustrative embodiments presented herein demonstrate the present invention. Other embodiments and variations based on the embodiments, concepts and principles set forth herein are within the scope of the invention. Additional embodiments, features and advantages of the present invention may be appreciated by reference to the following description and to the appended drawings and claims.